Complex MCA Aneurysms
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This video describes techniques for clip ligation of complex or very broad base small to medium size MCA aneurysms via bipolar coagulation, remodeling of the dome or aneurysmorrhaphy. This is a patient of mine who is 56 year old male, who was diagnosed with an incidental seven millimeter saccular or a semi fusiform aneurysm of the left MCA bifurcation. As you can see on these 3D reconstruction of the catheter angiogram, the aneurysm has a very short neck, but rather a very broad base. The aneurysm itself is actually multilobulated and has some fusiform features as it incorporates the portion of the proximal M2 branches. Let's review the intraoperative findings. In this case, the Sylvian fissure was open from the distal to proximal direction. All the arachnoids bands were widely dissected because of the complexity of this aneurysm and its shape, I expected that very much circumferential exposure of the dome and the aneurysm neck is necessary. Initially, I attempted to expose M1, which was exposed somewhat posterior actually, and deeper to the aneurysm here is the location of the aneurysm at the tip of my arrow. Here's the M1 branch and it's distal end. Because of the relatively short length of the M1, I expect that there will be few lenticulostriate arteries in the region and therefore I spent reason amount of time dissecting the distal M1 to make sure that the clip blades of the temporary clip are not going to interfere with the perforators or cause their injury. So here you can see the dissection along the distal M1. This is a relatively small amount of space to work through. Fixed retractors are avoided to minimize the risk of injury to the opercula areas. Here, you can see those perforating vessels that I expected. These lenticulostriate arteries are mobilized and adequate space for the clip blades of the temporary clip is created. Here is sharp dissection releasing the bands of these lenticulostriate arteries. Additional space is created for the clip blades. Now that I have adequate space there, I went ahead and dissected around the aneurysm dome. You can see the dome is here. It's very short neck. The adherent emphasage arteries are mobilized away from the neck. Now that I'm getting close to more high-risk maneuvers, the temporary clip was deployed. I assured myself that the blades are all the way across M1. You can see the distal portion of the aneurysm is very much incorporating the origin of M2. I dissected the dome of the aneurysm away from the surrounding cortex so I can see around the cortex toward the M1 above the aneurysm so I can make sure the final permanent clip blades completely exclude this very broad base aneurysm. The aneurysm is relatively baldness. I will have some difficulties seen around the aneurysm dome after the dome is completely dissected. I use bipolar forceps under irrigation and temporary occlusion of M1 to coagulate the dome and shrink it so I can see around the dome and be able to apply the clips more effectively. Here are the final attachments of the dome. I'll review the morphology of the aneurysm with you in a moment. Here's the M1 that is in view just over the aneurysm. The initial temporary clip was placed below the aneurysm. Here you can see that the distal neck of the aneurysm essentially is almost at the same level as the outflows of the temporal M2. This is M1. M2 is here. Here is M1 there again, and there is really minimal neck to work through. The emphasage arteries are again mobilized away. All the arachnoid bands at the neck and the origin of the temporal M2 are dissected. And you can see that again, this is a bulbous aneurysm. And here is the M2 exiting the aneurysm, essentially at the level of the dome. The low stature of this very broad base aneurysm created morphological challenges for placement of adequate definitive clip for exclusion of the dome. With this morphology in mind, I attempted coagulation of the dome to be able to create a more favorable morphology for application of the clip. Here, again, any manipulation did not reveal additional neck. Here is the aneurysmorrhaphy using bipolar forceps over the dome, especially the portion that is herniating superiorly immediately, complicating adequate clip placement. I attempted multiple clips, all of which had shortcomings. Even a J clip seemed to leave some aneurysm neck behind. Different angles of application and deployment were also attempted. You can see again, the neck very much comes to level of the dome. Here is further aneurysmorrhaphy so I can see over the aneurysm to be able to place the more medial clip blade adequately. I tried to place this curved clip, but still there was residual aneurysm herniating just below the clip blades superiorly. I could not push the clip blades toward M1 more because of the very short stature of the neck, close to the temporal M2 along the distal neck at the tip of the arrow. Subsequently I settled on an angle fenestrated clip so I can place the superior clip more toward M1. This left small entry into the aneurysm dome more proximally, which I thought I'll manage via additional clips. Here's a second clip to close the entry into the dome. Ultrasonography using the micro-Doppler device demonstrated some questionable flow within the dome. Another clip was placed at the fenestration. You can see there is small amount of flow on ICG in the aneurysm dome. FLOW 800 evaluation demonstrated good flow without any delay in the M2 branches. So I was satisfied that even though there is flow, quantitatively there is no compromise in the M2 branches. You can see the fluorescein angiography also demonstrated some small filling of the dome distally, potentially some flash filling. You can see more here in a delayed fashion within the dome. I placed additional clip across the dome to avoid filling in this area. Flow was maintained. Finally, an intraoperative angiogram was performed, which revealed complete exclusion of the aneurysm. Postoperative 3D catheter angiogram confirmed complete exclusion of the aneurysm without any complicating features. I believe the aneurysmorrhaphy was effective in this case to be able to shrink the dome so I can look over the superior portion of the dome for accurate deployment of the permanent clip blades. Thank you.
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